KVM: x86/mmu: Remove redundant spte present check in mmu_set_spte

Drop an unnecessary is_shadow_present_pte() check when updating the rmaps
after installing a non-MMIO SPTE.  set_spte() is used only to create
shadow-present SPTEs, e.g. MMIO SPTEs are handled early on, mmu_set_spte()
runs with mmu_lock held for write, i.e. the SPTE can't be zapped between
writing the SPTE and updating the rmaps.

Opportunistically combine the "new SPTE" logic for large pages and rmaps.

No functional change intended.

Suggested-by: Ben Gardon <[email protected]>

Reviewed-by: David Matlack <[email protected]>
Reviewed-by: Ben Gardon <[email protected]>
Reviewed-by: Sean Christopherson <[email protected]>
Signed-off-by: Mingwei Zhang <[email protected]>
Message-Id: <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>

1 files changed, 6 insertions, 10 deletions

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8568ae42e867..2f6458bca65d 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2776,17 +2776,13 @@ static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
 
 	pgprintk("%s: setting spte %llx\n", __func__, *sptep);
 	trace_kvm_mmu_set_spte(level, gfn, sptep);
-	if (!was_rmapped && is_large_pte(*sptep))
-		++vcpu->kvm->stat.lpages;
 
-	if (is_shadow_present_pte(*sptep)) {
-		if (!was_rmapped) {
-			rmap_count = rmap_add(vcpu, sptep, gfn);
-			if (rmap_count > vcpu->kvm->stat.max_mmu_rmap_size)
-				vcpu->kvm->stat.max_mmu_rmap_size = rmap_count;
-			if (rmap_count > RMAP_RECYCLE_THRESHOLD)
-				rmap_recycle(vcpu, sptep, gfn);
-		}
+	if (!was_rmapped) {
+		if (is_large_pte(*sptep))
+			++vcpu->kvm->stat.lpages;
+		rmap_count = rmap_add(vcpu, sptep, gfn);
+		if (rmap_count > RMAP_RECYCLE_THRESHOLD)
+			rmap_recycle(vcpu, sptep, gfn);
 	}
 
 	return ret;